Multimodal Meeting Monitoring: Improvements on Speaker Tracking and Segmentation through a Modified Mixture Particle Filter

In this paper we address improvements to our multimodal system for tracking of meeting participants and speaker segmentation with a focus on the microphone array modality. We propose an algorithm that uses Directions-of-Arrival estimated for each microphone pair as observations and performs tracking of an unknown number of acoustically-active meeting participants and subsequent speaker segmentation. We propose modified mixture particle filter (mMPF) for tracking of acoustic sources in the track-before-detection (TbD) framework. Trajectories of sound sources are reconstructed by the optimal assignment of posterior mixture components produced by mMPF in consecutive frames. Further, we propose a sequential optimal change-point detection algorithm which discovers speech segments in the reconstructed trajectories i.e., performs speaker segmentation. The algorithm is tested on a multi-participant meeting dataset both separately and as a part of the multimodal system. On the task of speaker detection in the multimodal setup we report significant improvement over our previous state of the art implementation.